Method of making coil type zipper fastener stringers



y 2, 7 J. E. BURBANK 3,316,870

METHOD OF MAKING COIL TYPE ZIPPER FASTENER STRINGERS Filed March 27, 1964 METHOD OF MAKING COIL TYPE ZIPPER FASTENER STRINGERS John E. Burbank, Middlebury, Conn., assignor to Scovill Manufacturing Company, Waterbury, Cnn., a corporation of Connecticut Filed Mar. 27, 1964, Ser. No. 355,197 2 Claims. (Cl. 112-265) This invention relates to a coil type zipper which is intended to describe any zipper where the fastener elements are formed of a continuous filament. It may be in the shape of a flattened coil or a meandering filament, which strictly speaking, is not a coil.

The general object of the invention is to provide an economical process of providing a coil type zip-per substantially enclosed by textile material. To this end, a simple flat tape rather than a more expensive Y-shape tape is employed. My improved process accomplishes the desired result in one operation on a sewing machine, which is generally cheaper and faster than a loom.

The process results in the production of the equivalent of a Y-tape in the final result, but without substantial additional cost because it is produced in the same operation which attaches the coil to the tape.

One advantage of this process is that it provides a zipper construction in which the width of the coils can be comparatively smaller because of the yarns running along the side edges of the coils, which yarns make a bearing for the slider.

The invention is especially well-suited to a coil type zipper wherein a cord assists in holding the covering material in place.

Other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawing, I have shown for purpose of illustration, one embodiment which the invention may assume in practice. In the drawing:

FIG. 1 is a front view with parts broken away of a completed zipper made in accordance with my invention;

FIG. 2 is a top plan view on a portion of a completed zipper stringer;

'FIG. 3 is a cross-section through the same completed stringer;

FIG. 4 is a diagrammatic view indicating the arrangement of the sewing threads;

FIG. 5 is a similar diagrammatic view with the needles in a different position;

FIG. 6 is a cross-sectional view indicating an early stage of my improved process;

FIG. 7 is a side view of the parts show in FIG. 6 with portions broken away; and

FIG. 8 shows a later stage in the process.

The complete zipper shown in FIG. 1 has two flat tapes 9 and 10 and a pair of interlocking stringers in the form of continuous coiled filaments 11 and 12. Each of the filaments encloses a continuous cord 13 which is relatively inextensible so as to give stability to the coil. Each coil is of generally oval shape in crosssection and the cord is at the inner portion of the oval while at the other end, are the interlocking heads 14. In order to prevent twisting of the coil convolutions relative to one another, it is desirable that the cords 13 be held tightly and this is one of the things which is accomplished by the present process.

In illustrating my improved process, I have indicated only diagrammatically certain portions of a sewing machine. These include two vertical reciprocating needles 15 and 16 and :a transversely operating looper 17. There United States Patent 0 will, of course, be suitable guides for the flat tapes and for the coil and its enclosed cord. These are not shown but there is indicated in end view, guides 18 for leading to the needle 15, a plurality of parallel yarns 19, herein shown as four in number.

In illustrating the process, reference is made to only one stringer employing the tape 9 shown at the left of FIG. 1. This simple flat tape is fed in overlapping relation with the coil '11, While the coil is aligned with the needle 16 so that said needle will pass through the tape and coil convolutions very close to the cord 13. The needle 15 is arranged to pass through the tape 9 to the outside of the coil. At the same time, the group of parallel yarns 19 is fed through guides 18 alongside the coil in line with the needle 15.

The needle 15 carries thread 20 While the needle 16 carries thread 21, and a looper thread 22 is fed to the machine in line with the needle 15 and below the yarns 19. In the stitching operation, needle 15 passes through the tape and through all of the yarns 19 to form a loop 23 while the thread 21 is carried by needle 16 through the tape and alongside the cord 13 to form a loop 24 at the bottom. At this stage, the looper 17 is projected through the loops 23 and 24 to catch the thread 22 and pull it back through loops 23 and 24 where it forms a loop 25 which is carried forward to the next stitch to be engaged and held by the succeeding loop of thread 22, in a well-known manner. This results in two lines of stitching 26 and 27, one being outside the coil and the other running through the coil. These two lines of stitching are interlocked and held on the front side of the coil by the looper thread 22. At the same time, there will be interlocked with thread 20, the group of parallel yarns 19 and by reason of proper tension applied to the looper thread 22, these yarns 19 will be pulled tightly over the coil 11 to produce the finished result as seen in FIGS. 2 and 3.

The coil is covered to such an extent by the yarns 19 and the thread 21 and 22 that it will be substantially concealed when the coil 11 is interengaged with its companion coil 12, as seen in FIG. 1.

As a result of the invention, it will 'be observed that I have provided an improved process which permits the use of a comparatively inexpensive hat tape, while at the same time producing a very desirable form of zipper stringer in a single operation on a comparatively highspeed sewing machine. Adequate coverage for the coil is provided and the cord inside the coil is bound tightly to prevent shifting of the coil convolutions relative to one another.

What I claim is:

1. The process of making a zipper fastener stringer in a sewing machine comprising (a) feeding a flat tape and a coil having a cord enclosed therein with the forward edge of the tape overlapping the coil;

(b) guiding a plurality of parallel yarns along the outside edge of the coil;

(c) passing parallel lines of stitching one through the tape and coil alongside the enclosed cord and another through the tape and said plurality of parallel yarns;

(d) interlocking said lines of stitching on the frontside of the coil opposite the tape by means of a third thread while applying sufficient tension to said third thread to pull said parallel yarns into covering relation with said coil and also to bind said cord tightly in the coil.

3 4 2. The process of making a zipper fastener stringer third thread while applying sufiicient tension to in a sewing machine comprising said third thread to pull said parallel yarns into (=21) feeding a flat tape and a C011 With the forward covering relation with said coiL edge of the tape overlapping the coil; (b) guiding a plurality of parallel yarns along the out- 5 References Cited by the Examiner slde edge Of the c011; UNITED STATES PATENTS (c) passing parallel lines of stitching one through the tape and coil and another through the tape and said plurality of parallel yarns;

(d) interlocking said lines of stitching on the front 10 JORDAN FRANKLIN Prlmary Exammer' side of the coil opposite the tape by means of a RICHARD J. SCANLAN, Assistant Examiner.

3,147,529 9/1964 Wilcken 24205.16 

1. THE PROCESS OF MAKING A ZIPPER FASTENER STRINGER IN A SEWING MACHINE COMPRISING (A) FEEDING A FLAT TAPE AND A COIL HAVING A CORD ENCLOSED THEREIN WITH THE FORWARD EDGE OF THE TAPE OVERLAPPING THE COIL; (B) GUIDING A PLURALITY OF PARALLEL YARNS ALONG THE OUTSIDE EDGE OF THE COIL; (C) PASSING PARALLEL LINES OF STITCHING ONE THROUGH THE TAPE AND COIL ALONGSIDE THE ENCLOSED CORD AND ANOTHER THROUGH THE TAPE AND SAID PLURALITY OF PARALLEL YARNS; (D) INTERLOCKING SAID LINES OF STITCHING ON THE FRONTSIDE OF THE COIL OPPOSITE THE TAPE BY MEANS OF A THIRD THREAD WHILE APPLYING SUFFICIENT TENSION TO SAID THIRD THREAD TO PULL SAID PARALLEL YARNS INTO COVERING RELATION WITH SAID COIL AND ALSO TO BIND SAID CORD TIGHTLY IN THE COIL. 